Hardy's paradox tested in the spin-orbit Hilbert space of single photons

Abstract

We test experimentally the quantum ``paradox'' proposed by Lucien Hardy in 1993 [Phys. Rev. Lett. 71, 1665 (1993)] by using single photons instead of photon pairs. This is achieved by addressing two compatible degrees of freedom of the same particle, namely its spin angular momentum, determined by the photon polarization, and its orbital angular momentum, a property related to the optical transverse mode. Because our experiment involves a single particle, we cannot use locality to logically enforce non-contextuality, which must therefore be assumed based only on the observables' compatibility. On the other hand, our single-particle experiment can be implemented more simply and allows larger detection efficiencies than typical two-particle ones, with a potential future advantage in terms of closing the detection loopholes.

7 pages, 5 figures and 1 table

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Cited by in corpus (3)

• Hardy's paradox as a demonstration of quantum irrealism
• A robust approach for time-bin encoded photonic quantum information protocols
• Polarization-based control of spin-orbit vector modes of light in biphoton interference